Sensors that estimate the current flowing in a conductor by sensing the related magnetic field are known in the art. Such sensors can be classified generally as open-loop or closed-loop.
Closed-loop systems, in which the magnetic sensor is used as a null detector and the system generates a field which cancels the magnetic field of the current to be measured, can be more accurate than open-loop systems but suffer from a large current drain necessary to generate the compensation magnetic field.
Open-loop systems typically use linear magnetic field sensors, such as Hall plates. The specially shaped conductors used in these systems are generally difficult and more expensive to manufacture. As previously mentioned, open-loop systems are also less accurate generally.
More generally, conventional current sensors suffer from other drawbacks, including hysteresis effects, limited over-current capabilities and higher cost related to, among other things, the requirement for magnetic shielding to suppress background fields
Therefore, there is a need for improved high current sensors.